The present invention relates to an armature of an electric motor such as an engine starter motor having an armature core and an armature coil wound thereon.
An example of a conventional armature of such motor is shown in FIGS. 2 and 3, in which an armature 1 includes an armature core 2 and an armature coil 3 wound thereon and is supported by a motor shaft 4 on which a commutator 5 is provided. A pair of steel rings 6 are fitted on an outer periphery of the armature coil 3, at opposite ends thereof through insulating tape 7.
In the conventional armature constructed as above, the steel rings 6 function to prevent the armature coil 3 from being radially outwardly scattered by centrifugal force applied thereto when the motor rotates. In order to electrically insulate the armature coil 3 from each steel ring 6, the insulating tape 7 is disposed therebetween.
The insulating tape 7 is wound on the outer periphery of the armature coil 3, which requires a time consuming work, practically.